Various methods for forming pasty products are already known in the food industry. A method is described, for example, in EP 1 576 883 B1 in which two forming plates are moved linearly toward each other to change the cross-section of the passage opening.
However, this method poses problems in the production of rounded food products, such as balls or cylindrically formed items with rounded ends or drop-shaped products. This is for the reason that slit-like, cat-eye-shaped cross sections are created at the extruded strand by the motion of the two knives relative to each other. The ends of the portion are therefore not rounded as is evident in particular from FIG. 9.
To produce round ends, for example, so-called diaphragms are also used having multiple separating elements that can move up and down in the form of an iris diaphragm. A respective device is composed of many individual components. Handling, i.e. assembly, disassembly and cleaning are therefore cumbersome. The diaphragm can further not be closed such that the individual components are superposed, which means that this device is not suitable to sever a food strand, i.e. cut it off. A respective device is often operated in a single lane. Should production be done in multiple lanes, then the parallel set-up of multiple individual diaphragms is necessary. The number of components required greatly increases accordingly. Such configurations are then very complex for the operator to assemble and to disassemble and are also very costly. A corresponding device is known, for example, from WO 2013/139853 A1.
Starting out from the aforementioned prior art, the present invention is based on the object to provide a device and a method that enable simple forming and partitioning of a pasty food strand, where improved shaping is simultaneously achieved.
The forming device for forming and partitioning a pasty food strand according to the present invention comprises more than two flat displacement elements superposed in the direction of transport of the food strand. The flat displacement elements are disposed closely one on top of the other, so that they can slide past each other and thereby also sever the strand of filling material, i.e. cut it off. The flat displacement elements are preferably formed as flat displacement plates. The flat displacement elements each comprise at least one opening through which the food strand can be transported in the direction of transport. In addition, the invention comprises a movement mechanism for moving the flat displacement elements on a respective curved path, such that the respective openings are movable relative to each other. The respective openings are movable relative to each other so that the cross-sectional area of the resulting overall opening of the superposed openings changes.
Due to the fact that more than two flat displacement elements with respective openings are used which are moved on a curved path, a cat-eye shaped overall opening is not created in contrast to prior art, but instead a preferably rounded polygon whose size can vary on its curved path in dependence of the motion of the flat displacement elements. This means, for example, that (with initially completely superposed openings) a rounded polygon is upon movement of the displacement elements on a curved path created from an initially round overall opening and can produce a nicer rounded shape than in prior art.
Due to the fact that the flat displacement elements are moved with the movement mechanism and can with their openings slide past each other, the flat displacement elements can not only form the food strand, but also cut it off completely. A separate cutting tool can therefore be dispensed with. The device according to the invention can be easily manufactured and is easy to handle and to clean. The forming device can be easily placed at the extrusion end of a filling machine such that the center of the overall opening and the center of the extrusion opening for the pasty food strand are in alignment. The forming device according to the invention can therefore also be easily retrofitted. The forming device according to the invention can furthermore be integrated into existing systems in an extremely space-saving manner. Different product shapes can be produced with one and the same device by actuating the movement mechanism and respective extrusion speeds differently, without this requiring any mechanical changeover. Already three flat displacement elements provide significant advantages. Preferably 3 to 6, more preferably 3 to 4 displacement elements are used.
The movement mechanism is configured such that the flat displacement elements are movable to a severing position A in which the openings are aligned relative to each other such that the cross-sectional area of the overall opening is zero, meaning that the free overall opening is no longer present and the food strand is severed. The flat displacement elements are movable from this position to an open position O in which the cross-sectional area of the overall opening has a predetermined maximum cross-section. This cross-section then corresponds to the maximum cross-section of the product. The predetermined maximum cross-section there preferably corresponds to the cross-section of the openings when they are totally superposed i.e. their centers are disposed in alignment to the center of the food strand or a respective extrusion opening, respectively. Products with different rounded shapes such as balls, cylindrically formed parts with rounded ends or drop-shaped products can thereby be created by the motion of the flat displacement elements from a severing position to an open position and a motion back to the severing position in dependence of the speed of the food strand.
During the motion of n flat displacement elements, where n∈|N, and n>2, from the open position O to the severing position A, the edges of the openings defining the overall opening can move from n sides in the direction toward the center M of the overall opening. During the motion of the flat displacement elements from the severing position A to the open position O, the edges of the openings can move toward n sides away from the center. Even and nice rounded shapes can be produced like this.
Advantageously, the openings in the flat displacement elements have a cross-sectional area which is approximately 10% smaller to 10% larger than the cross-sectional area of the supplied food strand or the extrusion opening creating the food strand and is preferably approximately equal in size. A maximum overall opening can thereby be provided which has at least the cross-section of the extrusion opening of a respective feed, so that any back-up of the food strand is avoided. The resulting area of the overall opening should be no greater than that of the extrusion opening of the food strand, so that the food does not exit laterally at the edge of the opening.
The openings preferably have an enclosed circumference so that multiple openings can be arranged in series. The openings are preferably configured to be round or oval, but have at least curved portions which then form the edges of the overall opening in order to be able to produce a nice rounded shape of the product.
If the displacement elements each have adjacently disposed multiple openings for multiple corresponding food strands, then multiple formed food products can be produced in a simple inexpensive manner parallel to each other with only one forming device and one corresponding movement mechanism.
The movement mechanism preferably comprises at least one rotary member, in particular a rotatable disc, on which the flat displacement elements are rotatably mounted. The displacement elements can according to a preferred embodiment be moved simultaneously therewith by using a rotary member on a curved path, which is simple and inexpensive to implement. The flat displacement elements are there distributed, for example, around the circumference of the rotary member, preferably at equal spacing. Different curved paths having different directions of movement thereby arise for the different displacement elements at a specific angle of rotation of the rotary member, i.e. in a predetermined time interval, such that the openings in the flat displacement elements can be moved relative to each other.
It is possible that the displacement elements are at their two oppositely disposed end portions rotatably mounted on a respective rotary member. For example, one rotary member can be driven and the other rotary member can rotate freely for guiding.
At least one rotary member should be drivable. It is advantageous if this rotary member can be driven in two directions of rotation, as, for example, a collision of a displacement element with a coupling axis of a subsequent displacement element is possible when coupling multiple displacement elements to one side of a rotary member. If the rotary member can be driven in two directions of rotation, then the device can be moved, for example, in one first direction of rotation from an open position to the severing position and be rotated in a direction opposite to the direction of rotation back from the severing position to the open position. Any collision can thereby be prevented. In addition, the rotary member must be moved in an angular range (e.g. 0°-110°) between the severing position and the maximum open position. However, it is also possible that multiple rotary members can be driven.
It is further possible that the movement mechanism on one side of the two sides comprises multiple rotary members between which the displacement elements are guided. At most one flat displacement element is at a front or rear side of the rotary members respectively coupled to its end portion. At its other end portion, the respective displacement element can by way of a respective guide (e.g. also co-traveling rotary members on the front or rear sides of which also always one displacement element is coupled) be entrained on the respective path. A respective arrangement allows the rotary member to be able to move continuously in one direction without the above-mentioned collision occurring. The drive of the multiple rotary members can be effected by coupling to one motor. However, two or more separate motors can also be used, where the shape of the products to be produced can then still be further influenced.
It is also possible that the coupling points of the flat displacement elements of the rotary member exhibit varying distances to the central axis of the rotary member. The shape of the product can again further be influenced thereby. A further possibility is that the openings in the flat displacement elements are not round but have a shape differing therefrom. When the coupling points then also revolve on different radii and the drive speed of the rotary member is adjusted accordingly, then products having a specific shape can be produced.
The device advantageously comprises a controller which can adjust the extrusion speed of the food strand in dependence of the position of the flat displacement elements. The shape of the products can be precisely adjusted by correlating the extrusion speed and the position of the flat displacement elements at a given point in time.
A filling machine is provided according to the invention for producing formed food with a forming device for forming and partitioning a food strand according to the invention. The filling machine comprises a hopper for receiving the pasty food mass, as well as a conveying device, e.g. a vane pump, that conveys the pasty food mass into a filling member, e.g. a stuffing tube or a filling flow divider with at least one extrusion opening. The displacement elements are then arranged in the direction of transport directly downstream of the extrusion opening. The displacement elements are disposed so close to the extrusion opening that there is sufficient play for the flat displacement element to freely slide past the outlet opening.
The guide for the displacement elements is advantageously configured such that the center M of the respective overall opening of the superposed openings and the center of the respective extrusion opening of the filling member are in alignment. A nice symmetrical shape can then be created, where the pasty mass can be extruded evenly over the entire cross-section of the extrusion opening without causing partial back-ups.
The filling member of the filling machine advantageously comprises a filling flow divider through which the pasty food mass is conveyed to multiple extrusion openings. The flat displacement elements than each also have multiple respective openings that are in alignment with the extrusion openings of the filling flow divider. Multiple products can thereby be produced in parallel in a simple manner.
The filling machine advantageously comprises a control device which controls the movement mechanism and the conveying device. The filling machine can there comprise a controller which is disposed within the filling machine and actuates both the movement mechanism and the conveying device. It is also possible to have the filling machine comprise a separate control device, where the movement mechanism is actuated by a separate controller and the two controllers are in one example coupled to each other to coordinate the functions of the movement mechanism, in particular the position of the individual displacement elements in dependence of time, as well as the functions of the conveying device, in particular the conveying speed, to each other depending on a desired product shape.
In the method according to the invention, the movement mechanism is actuated such that more than two flat displacement elements are moved from a severing position to an open position on a curved path, where the flat displacement elements are superposed with each other in the severing position such that the cross-sectional area of the resulting overall opening of the superposed openings is zero and the cross-sectional area of the overall opening in the open position has a predetermined maximum cross-section. The flat displacement elements can then again be moved from this open position on a curved path to the severing position. The food strand is then in the severing position severed, so that single products are created. During the movement of the displacement elements between the severing positions, the pasty food mass is moved through the extrusion opening of the filling member and through the adjoining expanding or tapering overall opening of the flat displacement elements.
The pasty food mass is advantageously continuously or in portions extruded, where in the severing position, the speed of the food strand relative to the flat displacement elements in the direction of transport T is reduced, and in one example, reduced to 0.
This can either be realized in that the food mass is extruded in portions, where the food flow is stopped or at least reduced when the displacement elements are in the severing position such that the food does not accumulate at the displacement elements. However, it is also possible that the forming device is configured in a certain section as being co-traveling in the direction of transport T, i.e. that the separating device can move at substantially the same speed as the strand of filling material, so as to prevent any back-up of the product. The extrusion member must for this be designed to be telescopic, so that the uppermost separating element and the extrusion opening are always disposed close together.
The openings can for severing the food strand be superposed in such a manner that the edges defining the respective openings slide past one another such that the food product is cut off. This means that the displacement elements are first moved on their curved path such that the overall opening reduces with the movement until the area of the overall opening becomes zero and the displacement elements are then moved even further along the path until the food product is cut off by the edges that move past each other. This is particularly advantageous for fibrous foods. But it is also possible that the displacement elements are moved on the curved path only until the area of the overall opening becomes zero. One respective guide is sufficient, for example, for foods of homogeneous consistency, as for example with potato dough.